The invention relates to a tiltable vehicle seat, especially for commercial vehicles, of the type which can be pivoted between an in-use position and a position facilitating easier vehicle access for boarding and exiting.
In a known vehicle seat of this type (German Patent Specification No. 3,507,894) the backrest is held pivotably on two brackets which are provided laterally on the seat cushion and which themselves are displaceable horizontally relative to the seat-cushion frame fastened on a seat underframe. The backrest frame and brackets are coupled to one another via pivoting levers, in such a way that the forward tilting movement of the backrests onto the seat cushion at the same time causes a horizontal displacement of the brackets and consequently of the backrest. In the erected position of use of the backrest, one of the two brackets is supported on a stop face of a toothed element and is thus secured against horizontal displacement. A hand lever for pivoting this toothed element is connected rigidly to the toothed element, which forms part of the actuating mechanism for locking and releasing the seat underframe relative to the vehicle floor. The toothed element is in engagement with a second toothed element, the pivoting movement of which is transmitted via a connecting rod to the catching claw for releasing and locking the seat underframe relative to the floor. A catching claw is arranged on the foot of each of the two rear underframe legs of the seat underframe, so that the transmission consisting of the second toothed element and of the connecting rod is present twice, once on each rear underframe leg. The two toothed elements are connected rigidly to one another by means of a coupling rod.
When the first toothed element is pivoted downwards by means of the hand lever, its pivoting movement results, on the one hand, in a freeing of the bracket and, on the other hand, via the two second toothed elements and the connecting rod, in a swinging of the two catching claws out of the vehicle-integral mounting on the vehicle floor. The backrest can now be tilted onto the seat cushion, and at the same time it is shifted rearwards relative to the seat-cushion frame as a result of the displacement of the brackets. The seat cushion, together with the swung-down backrest, can then be pivoted upwards about the front underframe legs of the seat underframe into approximately vertical alignment, the rear underframe legs swinging against the underside of the seat-cushion frame via coupling rods. This position of the vehicle seat serves to make it easier to mount the vehicle and alight from it, especially where buses or delivery lorries are concerned. A disadvantage of this arrangement is that the catching claws, in their swung-out position, project from the underframe legs and are a source of injuries, especially foot injuries, to the passengers.
An object on which the invention is based is to improve the construction of a vehicle seat of the type mentioned in the introduction, in such a way that any danger of injury on the vehicle seat in its swung-up access position is avoided.
In a vehicle seat of the above noted type, this object is achieved according to the invention, by providing a seat arrangement wherein the actuating mechanism is coupled to the backrest in such a way that the tilting movement of the backrest results in a swinging-out movement of the catching claw means and the erecting movement of the backrest results in a swinging-in movement of the catching claw means with respect to the mounting located on the vehicle, and wherein the catching claw means is arranged so that, in its swung-out position, it is arranged concealed.
In the vehicle seat according to preferred enbodiments of the invention, when the backrest is tilted after being released in the position of use the locking claw or locking claws are necessarily swung out of the mounting integral with the vehicle and changed over into a masked position, in which they are drawn into the seat-cushion frame or, if a seat underframe is connected to the seat-cushion frame, into the seat underframe. The changeover takes place automatically, in a way substantially improving the ease of operation, by swinging down the backrest, specifically as early as when the seat-cushion frame is still in its position of use. With the seat-cushion frame raised vertically and the backrest swung to, each catching claw no longer projects into the access space, but is set back completely behind seat parts, so that it is masked by large-surface seat parts, at least in the boarding and alighting direction, and can no longer be touched. When the vehicle seat is swung back, each catching claw is again brought out of its concealed swung-out position for swinging into the floor mounting only as a result of the erection movement of the back-rest, but the seat-cushion frame has then already assumed its position of use again. The positive coupling of the pivoting movements of the catching claw and backrest ensures, that, when the seat is raised, each catching claw does not remain extended, even inadvertently, and does not project into the access region for the vehicle passengers.
Measures are provided in certain preferred embodiments of the invention which make it impossible, on the one hand, for the vehicle seat to be released from the floor too early, that is to say before the backrest is tilted sufficiently far towards the seat cushion, and, on the other hand, for the catching claw to be swung out too early during the tilting back of the seat, that is to say before the seat-cushion frame or its underframe has touched the vehicle floor. Injuries during the tilting of the vehicle seat can also thereby be prevented reliably. A spring tensioned during the tilting of the backrest and functioning as a drive for the catching claw, is provided in certain preferred embodiments of the invention, which ensures that the catching claw swings into the mounting on the vehicle floor automatically and reliably, as soon as the locking of the catching claw in its swung-out position at the end of the return movement of the backrest into the erect position of use is cancelled again.
On vehicle seats of which the seat-cushion frame is connected to the vehicle floor via a seat underframe, a catching claw is arranged on each rear underframe leg of the seat underframe in a known way. In this case, in an expedient embodiment of the invention, the catching claws are arranged pivotably inside the hollow underframe feet, so that, in their swung-out position, they swing completely into the underframe feet. The fact that the rear underframe feet swinging up into the vertical access position together with the seat-cushion frame are covered with flexible foam also contributes to increased safety according to certain preferred embodiments.
The constructive measures of the preferred embodiments described below further contribute as a whole to a productively simple and mechanically reliable embodiment of the actuating mechanism for the catching claws.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.